Synchronizing appartaus



Sept. 4, 1928. 1,683,158

yv. BRUCKEL s'mcunomzme APPARATUS File u y 1 1925 s SheetsSheet 1 J 2Q J 5:!

13; I f 2 l5 25 Inventm":

Waldemar" Br-CacKe I;

H is Atnorneg- Sept. 4, 1928. 1,383,158

W. BRUCKEL 'smcimorirz'me' APPARATUS iled July 17, 1925 a Sheets-Sheet 2 In Verwtor- \lvalzrleTn-ar- BT-(lckel His Attorney- Sept. 4, 1928.

1,683,158 w. BRUCKEL SYNCHRONIZING APPARATUS Filed July 17, 1925 3 Sheets-Sheet 3 Pig/0. M J [K W) MAT T Tb INDICATORS T0 INDICATOR 52 c 4 ch 50 T0 INDICATOR $49 F i 5' J $48 46' Inventor": Waldemar BrLickel His Attorney.

Patented Sept. 4, 1928.

UNITED STATES PATENT OFFICE.-

WALDEHAB BRU'CKEL, F BERLIN, GERMAQNY, ASSIGNOB T0 GENERAL I COMPANY, A CORPORATION 013' NEW YORK.

snwnnomzme urannrus Application fled July 17, 1925, Serial No. 44,226, and in Germany August 6, 1924.

M invention relates to apparatus for controlling the interconnection of alternating apparatus for causing two electrical systems to be interconnected when a predetermined relation has been established between their electrical conditions.

It is well known that two alternating current systems may be interconnected without ditficulty when a predetermined relation has been establis d between their electrical conditions o in other words, when they are in phase and operating at substantially the same voltage and'frequency. In the past it has been proposed to control interconnection of the systems by means of apparatus adapted to produce an effect dependent on the sum of or the difference between the system voltages,by apparatus operable in response to'E 111 and to E E sine Where E and E are the system voltages and (,0 is the angle of phase displacement between these voltages, or by means of a phase indicator, a time delay element being utilized in connection with the last two arrangements to ensure that the control circuit of the s nchronizing switch is not closed until the system frequencies are substantially equal. In accordance with my invention, interconnection of the systems is controlled by apparatus operable in accordance with the quantities E E sine and E E cosine ,0. The advantages of this apparatus will appear as my invention is considered in detail.

My invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope will be pointed out in the appended claims.

Referring to the drawings, Fig. 1 shows a number of curves and vectors which illustrate the conditions existing when two systems are Figs. 2 and 3 for ensuring that the systems are interconnected only when they are operating at substantially the same voltage; Figs. 8 and g illustrate details of mod fications of my inventionsjand Fig. 10 illustrates diagramand subsequent to'the time T are indicated by curves 1 to 7 inclusive. Of these curves, 1 represents the phase difference between the voltages E and E curves 2 represent thesum of E and E curves 3 represent the difference between E and E curve 4 represents E E cosine curve 5 represents E E sine (p, and curves 6 and 7 represent the squares of the voltage difference and voltage sum respectively. The points at which the curve 5 intersects the time axis are indicated by the letters a, 0, 6, g and z and the points at which the curve 4 intersects the time axis are indicated by the letters 5, d, f and h. The oscillations of the curves 1 to 7 will depend on the difference between the frequencies of the voltages E and E and will become slower as these frequencies approach equality.

It will be observed that before the time T the voltage E lags behind the voltage E that the phase difierence between the voltages becomes zero at the time T; and that after the time T the voltage E leads the voltage E Zero phase displacement thus definltely indicates the moment at which the voltages E, and E are in phase. If the frequency of voltage E is slowly ap roaching that of thevoltage E there will a so be substantial equality of the .two frequencies at the time T and a phase indicator may be utilized to cause interconnection of the two systems. In order to ensure that the systems are not interconnected when the frequencies of the two systems are substantially different, however, it is necessary to utilize a time delay element for preventing operation of the phase indicator when the system frequencies rapidly pass through a condition of equality.

'As previously indicated, it has been pro-- posed to utilize either the vector sum of or the vector difference between the system voltages to control the interconnection of the systems. In this method of synchronizing the quantities represented by the curves 6 and 7 are utilized, and, while the voltage sum, and,

difference attain the maximum and minimum value respectively, at the time T, it will be 'noted that the curves 6 and 7 which represent the squares of the voltage sum and difference are comparatively flat at the instant T so that a device operating in response to change in these quantities is not very accurate. For this reason, more sensitive and accurate means of selecting the time of interconnect-' ing the systems have been considered.

To ensure the more accurate operation of a synchronizing apparatus, a device operable in response to variation in the quantity E E sine 4: has been used. This quantity is my inventiondiffers from those just described in that it comprises electroresponsive means such as an element 8 operable in'response to changes in the value of the quantity E E sine qt and electrorespon'sive 'means such as an element 9 operable in accordance with the quantity E E cosine qb. It will be observed that the element 8 comprises a rotatable disk 10, a coil 11 wound on a core 12 and connected to a system 13 through a transformer 14, and a coil 15 wound on a core 16 and connected to a system 17 through a transformer 18 and a reactor 19; and that the element 9 comprises a rotatable disk 20, a coil 21 wound on the core 22 and connected through the transformer 14 to the system 13, which is to be synchronized with the system 17, and a coil 23 wound on a core 24 and connected to the system 17 through the transformer 18 and a resistor 25. With these connections, the torque exerted on the disk 10 prior and subsequent to the time T varies in accordance with curve 5 of Fig. 1 and the torque exerted on the disk 20 during this interval varies in accordance with curve 4. A switch 26 operable in response to actuation of elements 8 and 9 is provided for interconnecting the systems 13 and 17 when the proper relation has been established between their,

electrical conditions. The manner inwhich this result is accomplished will be readily understood upon consideration of Fig. 3.

Fig. 3 shows a spiral spring 27 connected at one end to the shaft 28 of the disk 10 and small value, the member 29 is maintained in its illustrated position and the coil 23 causes a torque which is proportional to the quantity E E cosine to be exerted on the disk 20. 7

'sine b has its maximum value or has a predetermined high value. A time delay element shown as a damping magnet 42 is arranged to 8 prevent engagement of contacts 40 and 41 when a substantial difference exists between the frequencies of voltages E and E and the value of the quantity E E cosine oscillates at a comparatively high rate. The operating 8 circuit of the synchronizing switch 26 is controlled through contacts 40 and 41.

With these connections, closure of contacts 40 and 41' is prevented by short circuiting of coil 23 when the quantity E E sine has a i high value and by engagement of pin 39 with stop 38 when the quantity E, E cosine 5 has a negative value and the disk 20 tends to rotate in a clockwise direction. Instead of being arranged to short circuit the coil 23, the 5 disk 10 may be arranged to control contacts 310, 320, 330 and 340 connected in series with the contacts 40 and 41 in the operating circuit of the synchronizing switch as shown -in Fig.9. In either case actuation of the 1 and E An important advantage of this arrangement is that, when a very considerable difference exists between the frequencies 1 of E l and E and the quantities E E sine b and E E cosine d oscillate in value at a very 7 high rate, the disks 10 and 20 remain in their 'rest positions due to their inertia and any danger of the synchronizing switch being 1 closed under these conditions is obviated.

It is sometimes desireable to compensate for the time delay between engagement of contacts 40 and 41 and closure of the synchronizing switch 26. This result may be produced 1 by any suitable means such as control elements arranged to operate with magnetic fields displaced in phase to produce early closure of contacts 40 and 41. One way of doing this is to replace the reactor 19-of Fig. 2 by a combination of resistance and reactance such that the fluxes in the core parts 12 and 16 are differently displaced. Operation of the element 8 is then in accordance with the product E E sin i +12.) where n, 1

represents the angular change in flux displacement or advance. This is in effect equivalent to moving the curve 5 of Fig. 1 to the left so that itcuts the time axis between d and e instead of at 6. Another possible means ofaccomplishing this time compensat ing result is to connect the member 29 of the element 8 to the shaft 28 through a friction coupling, shown in Fig. 8 as comprising a spring pressed pinion 70 mounted on the end of the member 29 and arranged to engage a gear sector 71 which is secured to the shaft 28. The end of the spring-27, instead of being secured to the member 29, is secured to a fixed support 72. With this arrangement it is possible to limit the movement of the member 29 by means of a stop 73, thus en- I abling' it to return quickly to its position of rest. A further means of accomplishing this time compensating result is by means of a pointer which is illustrated in Fig. 3 as stationary stops 74 and which in effect displaces the holder or clamping point of the reset spring by a certain amount so that in case of maximum deflection the rest position of the disk 10 is displaced either to'the right or left depending on the direction of rotation. 1

. is energized. When the disk 10 swings s. 4 and 5 show an arrangement for indicating at a remote location-the operating conditions of the apparatus. This arrangement comprises conductors -43 connected to the systems 13 and 17 in any suitable manner to apply the sum of the system voltages either to a circuit comprising resistor 44 and operating coil 45 of a relay switch 46 or to a circuit comprising resistor 47 and operating coil 48 of a relayswitch 49. Energization of the operating coils 45 and 48 is controlled by contacts 50 and 51 and by contacts 52 and 53 respectively. Engagement of contact 50 with contact 51, or of contact 52 with contact 53 is produced through means comprising amovable member 54 pivoted at 55 and arranged to support at its free end a drag magnet 56 located in proximity to the disk 10.

With this arrangement, a torque dependent on the rotational speed of the disk 10 is exerted on the member 54 and if the rotation of the disk 10 is counterclockwise when the frequency of voltage E becomes equal to that of E and the voltage sum reaches its maximum value, the contact 50 is caused to engage contact 51 and switch operating coil backward, however, the voltage sumhas attained a value incapable of producing operation of relay switch 49 even though the contact 52 be caused to engage contact 53. Therefore if the frequency of the voltage E is permanently too high, the switch 46 is closed during intervals of time which become longer as the frequencies of voltages E and E approach equality and the switch 49 is maintained in its illustrated open position. When the frequencies of'voltages E and. E

become very nearly equal, the disk 10' moves so slowly that little or no torque is exerted on the member 54. This member is therefore allowed to assume its illustrated position and the element. 8 is free to control the connections of coil 23 in a manner to produce operation of the synchronizing switch at the proper time.

If the frequency of voltage E is lower than that of voltage 13,, the switch operating coil 48 is energized through intervals dependent on the frequency difference, the switch 46 is maintained in its open position, and the member 54 is allowed to assume its illustrated position when the two frequencies become substantially equal. An operator controlling the electrical conditions of the system 13 or the system 17 at a location remote from the paralleling apparatus is thus kept informed at all times as to the relations exists ing between the systems.

Figs. 6 and 7 show a voltage balance device such as a differential relay comprising motor elements 57 and 58 which are arranged to exert opposed torques on a rotatable armature disk 59 mounted on a shaft 60. The motor element 57 comprises a coil 61 wound on a core 62 and connected to the system 17 through the potential transformer 18. The

motor element 58 comprises a coil 63 wound on a core 64 and connected to the system 13 through the potential transformer 14. A pin 65 mounted on the disk 59 is provided for. I

cause the operating coils 45 and 48 of relay switches 46 and 49' to be energized to indicate at a remote point the voltage relations existing between systems 13 and 17 as shown in Fig. 10. It will be readily understood that the disk 59 need not be arranged to control contacts 31 to 34 directly but may be utilized to control auxiliary contacts connected in parallel with the aforementioned contacts.

It is desirable to utilize the relay switches 46 and 49 not only to transmit signals indicating the frequency relation between the systems 13 and-17 as previously described, but also to utilize relay switches such as 46 and 49 for transmitting signals indicating the voltage relation existing between these systems. This result may be accomplished by connecting as shown in Fig. 10, the contacts 50', 51, 52' and 53 to the relay switch operating coils 45 and 48 such a manner that when the contacts are closed one of the voltages to be compared is applied to one of these coils. With these connections, signalling devices energized through switches 46 and 49 will be operated in a manner to indicate the voltage relation existing between the systems 13 and 17 and. a perator located ting the part of the apparatus illustrated by Figs. 2, 3 and 4 to function in the manner previously set forth and cause paralleling of the systems 13 and 17 when the proper relation has been established between their electrical conditions. The fact that the switch 26 has closed may be determined by ascertaining that further adjustment in the frequency of one of the systems increases its power current while further adjustment in its voltage produces a change in its wattless current. Any other suitable means may of course be utilized to facilitate control of the systems at locations remote from the paralleling apparatus.

The embodiment of the invention lllustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the different conditions encountered in its use and I therefore aim to cover by the appended claims all IIIOdlfications withinzthe true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An apparatus for paralleling two alter- F nating current systems comprising one element and means for operating it in accordance with the product of the voltages of said systems and the sine of the angle by which these voltages differ in phase, another element and means for operating it in accordance with the product of said voltages and the cosine of said angle, and means for rendering said last mentioned element inoperative when the product of said voltages and the sine of said angle exceeds a predetermined value. 1

2. An apparatus for controlling the interconnection of two alternating current sys tems comprising interconnecting means, an element and means for operating it in accordance with the product of the voltages of said systems and the sine of the angle by which these voltages differ in phase, another element and means for operating it in accordance with the product of said voltages and the cosine of said angle, means operated by said last mentioned element for causing actuation of said interconnecting means, and means for rendering said last mentioned element inoperative when the product of said voltages and the sine of said angle exceeds a predetermined connection of two alternating current systems comprising interconnecting means, an

element and means for operatin it in accordance with the product of the voltages of said systems and the sine of the angle by which these voltages differ in phase, another element and means for operatin it in accordance with the product of sai voltages and the cosine of said angle, means operated by said last mentioned element for causing actuation of said interconnecting means, means for rendering said last mentioned element inoperative .when the product of said voltages and the sine of said an le exceeds a predetermined Value,'and time delay means associated with said last mentioned element for preventing actuation of said interconnecting means when the difference between the frequencies of said systems exceeds a predetermined value.

4. An apparatus for paralleling two alternating current systems comprising one element and means for operating it in accordance with the product of the voltages of said sgstems and the sine of the angle by which t ese voltages differ in phase, an element including a rotatable armature and means forv causing a torque dependent on the product of said voltages and the cosine of said angle to be exerted through said armature, means for rendering said last mentioned element inoperative when the product of said voltages and the sine of said angle exceeds a predetermined value, and means operated by said armature for causing said systems'to be interconnected only when the product of said voltages and the cosine of said angle has a predetermined value and sense.

5. An apparatus for paralleling two alternating current systems comprisin one element and means for operating it 1n accordance with the product of the voltages of said systems and the sine of the angle by which these-voltages differ in phaseyan element including a rotatable armature and means for causing a torque dependent on the product of said voltages and the cosine of said angle to be exerted through said armature, means for rendering said last mentioned element inoperative when the product of said voltages and the sine of said angle exceeds a predetermined value, means operated by said armature for causing said systems to be interconnected only when the product of said voltages and the cosine of said angle has a predetermined value and sense, and means for opposing said torque to prevent operation of said interconecting means when a predetermined difference exists between the frequencies of said systems.

6. An apparatus for paralleling two alternating current systems comprising one element and means for operating it in accord-.

ance with the product of the voltages of said systems and the sine of the angle by which these voltages differ in phase, an element including a disk armature and means comprising one coil arranged to be connected to one of said systems and another coil-arranged to be connected to the other of said systems through a resistor for causing torque to be exerted on said disk, means arranged to cause said systems to be interconnected only when said torque is exerted in a predetermined direction, and means controlled by said first mentioned element to short circuit one of said coils when the product of said voltages and the sine of saidangle exceeds a predetermined value. 7

7. In an apparatus for paralleling two al ternating current systems, an element including a disk armature and means comprising one coil arranged to be connected to oneof said systems and another coil arranged to be connected to the other of said systems through reactance means for causing a torque to be exerted through said disk, an element lIlClIJding a disk armature and means comprising one coil arranged to be connected to one of said systems and another coil arranged to be connected to the other of said systems through resistance means for causing a torque to be exerted through said second mentioned disk, and means arranged to prevent operation of said second mentioned element whenthe torque exerted through saidfirst' v be connected to the other of said systems through reactance means for causing a torque to be exerted through said disk, an element including a disk armature and means comprising one coil arranged to be connected to one of said systems and another coil arranged to be connected to the other of said systems through resistance means for causing a torque to be exerted throughsaid second mentioned disk, means arranged to prevent operation of said second mentioned element when the torque exerted through said first mentioned disk exceeds a predetermined value and torque having a predetermined sense is exerted through said second mentioned disk, and a drag magnet for preventing operation of'said second mentioned element to cause interconnection of said systems when the diflerence between their frequencies exceeds a predetermined value. a

9. In an apparatus for paralleling two alternating current systems, an element including a disk armature and means comprising one coil, arranged to be connected to one of said systems and another coil arranged to be connected to the other of said systems through reactance means for causing atorque to be exerted through said disk, an element including a disk armature and means comprising one coil arranged to be connected to one of said systems and another coil arranged to be connected to another of said systems through 1 resistance means for causing a torque to be exerted through said second mentioned disk, means arranged to prevent operation of said second mentioned element when the torque exerted through said first mentioned disk exceeds a predetermined value and the torque exerted through said second mentioned disk has a predetermined value and sense, and means for biasing said disks to predetermined positions.

10. An apparatus for paralleling two alternating current systems comprising one element and means for operating it in accordance with the product of the voltages of said systems and the sine of the angle by which these voltages differs in phase, another element and means for operating it in accord-- ance with the product of said voltages and the cosine of said angle, means for rendering said last mentioned element inoperative when the product of saidvoltages and the sineof said angle exceeds a predetermined value, and signal transmitting means controlled by said first mentioned element for indicating at a location remote from said apparatus the relation between the electrical conditions of said systems.

11. In an apparatus for paralleling two alternating current systems, the combination of a disk armature and means including one coil arranged to be connected to one of said systems and another coil arranged to be connected to the other of said systems through a reactor for producing rotation of said armature, an element comprising means connected and arranged to produce a torque dependent on the product of the voltages of said systems and the cosine of the angle by which said Voltages are displaced in phase from one another, and means controlled in accordance with the position of said armature for controlling the operation of said last mentioned element.

12. In an apparatus for paralleling two alternating current systems, the combination of an element comprising a disk armature and means including one coil arranged to be connected to one of said systems and another coil arranged to be connected to the other of said systems through a reactor for producing rotation of said armature, an element comprising means connected and arranged to produce a torque dependent on the roduct of the voltages of said systems and the cosine of the angle by which said voltages are displaced in phase from one another,

means controlled in accordance with the position of said disk for controlling the operation of said last mentioned element, and sig- I 13. In an apparatus for nal transmitting means controlled by said first mentioned element for indicating at a location remote from said apparatus the relation between the frequencies of said systems. aralleling two alternating current systems, t e combination of a disk-armature and means includin one 0011 arranged to be connected to one 0 said systems and another coil arranged'to be connected to. the other of said systems through a reactor for producing rotation of said armature, and means comprising a drag magnet arranged to be moved in response to rotation of said disk for indicating the relation between the electrical conditions of said systems.

14. An apparatus for paralleling two alternating current systems comprising one'element and means for operating it in accordance with the roduct of the voltages of said s stems and t e sine of the angle by which 1: ese voltages difi'er in phase, another element and means for operatin it in accordance with the product of said voltages and the cosine of said angle, means for rendering said last mentioned element inoperative when the product of said voltages and the sine of said angle exceeds a predetermined value, and means arranged to operate in accordance with the resultant of said voltages for rendering said last mentioned element inoperative when said voltages are not equal.

15. An apparatus for paralleling two alternating current systems comprising one element and means for operating it in accordance with the roduct of the voltages of said s stems and t e sine of the angle by which t ese voltages differ in;phase, another elementand means for operatin it in accordance with the product of sai voltages and the cosine of said angle, means for rendering said last mentioned element inoperative when the product of said voltages and the sine of said angle exceeds a predetermined value, means-for indicating the relation between the electrical conditions of said systems, and means arranged to operate in accordance with a resultant of said voltages for rendering said last mentioned element inoperative when a predetermined. diflerence exists between t ese voltages differ in phase, another ele-- ment and means for operatin it in accordance with the roduct of sai voltages and the cosine of said an 1e, means for rendering I said last mentioned e ement inoperative when the product of said voltages and the sine of said angle exceeds a predetermined value, signaling means, a device including a disk armature and means comprising one coil adapted to be connected to one of said systems and another coil adapted to-be connected to the other of said systems for producing rotation of said disk, and means controlled by the movement of said disks for rendering said last mentioned element inoperative when a predetermined diflerence exists between said voltages and for controlling said signaling means to produce an indication of said difi'erence.

17. Synchronizing means for two electric circuits comprising switching means for connecting the circuits and electroresponsive means for controlling the switching means comprising windings connected and arranged to produce efl'ects respectively proportional to the product of the voltages of the circuits and the sine of the phase angle between the volta es and to the product of the voltages and t e cosine of said phase angle.

- 18. An apparatus for paralleling two alternating current circuits comprising electroresponsive means having a movable member arranged to be actuated in accordance with the product of the voltages of said circuits and the cosine of the phase angle between the voltages, and a cooperating electroresponsive means having a movable member arranged to be actuated in accordance with the product of said voltages and the sine of said angle.

In witness whereof, I have hereunto set my hand this 3d day of July 1925.

WALDEMAR BRUCKEL. 

